The present invention relates to a device for confirming the fitting of an electric connector used in an electric wiring in a vehicle.
In an electric connector, a pair of mating connector housings are fitted together so as to connect together female and male metal terminals received respectively in the connector housings. In order to ensure such an electrical connection, a locking device is provided between the two housings to prevent them from becoming disengaged
FIG. 5 shows a conventional locking device. A locking arm b, deformable upwardly and downwardly, is provided on an outer peripheral wall of a male connector housing a, and a retaining hole f is formed in a hood e of a female connector housing d. A retaining projection c of the locking arm b is engageable in the retaining hole f. When the depth of fitting of the housing a into the hood e reaches a predetermined level the retaining projection c is engaged in the retaining hole f to make the male connector housing a and the female connector housing d a single locked mechanism.
The assembly and fitting operations of the electric connector are performed manually. Since numerous connectors normally must be assembled, some connector products may be in an unlocked condition resulting from an imperfect fitting due to operator error. It is difficult to discover such unlocked products visually during a subsequent inspection stage. Another problem is that the locking strength between the male and female housings can be increased by forming the locking arm b into a lever-like shape whose opposite ends are supported. However, if the locking strength between the male and female housings is excessive, this excessive locking strength, together with the resistance offered by the metal male and female terminals, makes the fitting operation of the housings difficult. Therefore, the locking strength heretofore has been purposely limited. As a result, when a force E perpendicular to the arm b is imparted thereon, the locking arm may be released inadvertently.
This problem of the locking between the connector housings becoming inadvertently released must be avoided, particularly when the electric connector is used in a wiring system for an air-bag device in a vehicle. Further, imperfect fitting and inadvertent release of the locking mechanism cannot be tolerated because of safety considerations.